A new report from the state Department of Toxic Substances Control confirms previous findings that methane and other gases underneath the much-delayed Belmont Learning Center near downtown Los Angeles can be safely mitigated.
Levels of arsenic and lead in the soil at the unfinished high school are "below health risk levels," said the report, which is considered a precursor to the resumption of construction. The high school, which was renamed Vista Hermosa in May, sits above an old oil field and an earthquake fault.
The report cautions that hydrogen sulfide and methane gases have been found deep below the ground's surface -- a discovery that halted construction in 2000. Hydrogen sulfide, which is toxic in low levels, can build up in enclosed spaces. Methane can catch fire, explode or cause suffocation, the study said.
The report, which was based on tests conducted in August and September, echoed earlier findings that those two potentially harmful gases must and can be contained, collected and monitored. It mentions 11 possible solutions, including active or passive venting systems, a membrane barrier underneath building foundations and chemicals and filters.
